Import two patches from Peter Oh to allow setting channel
bandwidth in the way it already works for managed interfaces.
This fixes mesh interfaces on 802.11ac devices always coming up in
VHT80 mode.
Add a patch to allow HT40 also on 2.4GHz if noscan option is set, which
also skips secondary channel scan just like noscan works in AP mode.
Signed-off-by: Daniel Golle <daniel@makrotopia.org>